1. Field of the Invention
The invention generally relates to the field of toys for detecting and signaling changes in ambient light level during a play mode of operation.
2. Description of the Prior Art
It is well known to have toys that are responsive to differences in light levels as indicated by the prior art listed below.
U.S. Pat. No. 3,064,390 shows an electrical toy gun controlled in part by a switch and in part by a light sensitive device.
U.S. Pat. No. 3,130,803 shows a toy tracking vehicle adapted to follow a path defined by light and dark areas.
U.S. Pat. No. 3,274,729 shows a doll having photocell actuated sounding means.
U.S. Pat. No. 4,147,996 shows a current controlled oscillator.
U.S. Pat. No. 4,199,753 shows an integrated circuit for detecting changes in light intensity.
U.S. Pat. No. 4,479,329 shows a toy including motion detecting means for activating the toy.
U.S. Pat. No. 4,659,919 shows a noise generating toy including optical sensors to detect the intensity of light in first and second optical fields, respectively.
U.S. Pat. No. 4,662,854 shows a self-propellable toy and arrangement for controlling the toy by an on-board infrared light transmitter and receiver.